```{index} single: nextkey; Config function ``` ```{index} single: Config::nextkey; Perl function ``` # nextkey Tied-hash iterator: return the next key after `FIRSTKEY`. ## Synopsis ```perl while (my ($k, $v) = each %Config) { ... } ``` ## What you get back The next key in the current iteration, or `undef` when the walk is exhausted. ## Edge cases - Calling `NEXTKEY` without a prior `FIRSTKEY` starts from wherever the hash's internal iterator happens to be. ## Differences from upstream Fully compatible with upstream.